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v6.13.7
  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * arch/arm/include/asm/mcpm.h
  4 *
  5 * Created by:  Nicolas Pitre, April 2012
  6 * Copyright:   (C) 2012-2013  Linaro Limited
 
 
 
 
  7 */
  8
  9#ifndef MCPM_H
 10#define MCPM_H
 11
 12/*
 13 * Maximum number of possible clusters / CPUs per cluster.
 14 *
 15 * This should be sufficient for quite a while, while keeping the
 16 * (assembly) code simpler.  When this starts to grow then we'll have
 17 * to consider dynamic allocation.
 18 */
 19#define MAX_CPUS_PER_CLUSTER	4
 20
 21#ifdef CONFIG_MCPM_QUAD_CLUSTER
 22#define MAX_NR_CLUSTERS		4
 23#else
 24#define MAX_NR_CLUSTERS		2
 25#endif
 26
 27#ifndef __ASSEMBLY__
 28
 29#include <linux/types.h>
 30#include <asm/cacheflush.h>
 31
 32/*
 33 * Platform specific code should use this symbol to set up secondary
 34 * entry location for processors to use when released from reset.
 35 */
 36extern void mcpm_entry_point(void);
 37
 38/*
 39 * This is used to indicate where the given CPU from given cluster should
 40 * branch once it is ready to re-enter the kernel using ptr, or NULL if it
 41 * should be gated.  A gated CPU is held in a WFE loop until its vector
 42 * becomes non NULL.
 43 */
 44void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr);
 45
 46/*
 47 * This sets an early poke i.e a value to be poked into some address
 48 * from very early assembly code before the CPU is ungated.  The
 49 * address must be physical, and if 0 then nothing will happen.
 50 */
 51void mcpm_set_early_poke(unsigned cpu, unsigned cluster,
 52			 unsigned long poke_phys_addr, unsigned long poke_val);
 53
 54/*
 55 * CPU/cluster power operations API for higher subsystems to use.
 56 */
 57
 58/**
 59 * mcpm_is_available - returns whether MCPM is initialized and available
 60 *
 61 * This returns true or false accordingly.
 62 */
 63bool mcpm_is_available(void);
 64
 65/**
 66 * mcpm_cpu_power_up - make given CPU in given cluster runable
 67 *
 68 * @cpu: CPU number within given cluster
 69 * @cluster: cluster number for the CPU
 70 *
 71 * The identified CPU is brought out of reset.  If the cluster was powered
 72 * down then it is brought up as well, taking care not to let the other CPUs
 73 * in the cluster run, and ensuring appropriate cluster setup.
 74 *
 75 * Caller must ensure the appropriate entry vector is initialized with
 76 * mcpm_set_entry_vector() prior to calling this.
 77 *
 78 * This must be called in a sleepable context.  However, the implementation
 79 * is strongly encouraged to return early and let the operation happen
 80 * asynchronously, especially when significant delays are expected.
 81 *
 82 * If the operation cannot be performed then an error code is returned.
 83 */
 84int mcpm_cpu_power_up(unsigned int cpu, unsigned int cluster);
 85
 86/**
 87 * mcpm_cpu_power_down - power the calling CPU down
 88 *
 89 * The calling CPU is powered down.
 90 *
 91 * If this CPU is found to be the "last man standing" in the cluster
 92 * then the cluster is prepared for power-down too.
 93 *
 94 * This must be called with interrupts disabled.
 95 *
 96 * On success this does not return.  Re-entry in the kernel is expected
 97 * via mcpm_entry_point.
 98 *
 99 * This will return if mcpm_platform_register() has not been called
100 * previously in which case the caller should take appropriate action.
101 *
102 * On success, the CPU is not guaranteed to be truly halted until
103 * mcpm_wait_for_cpu_powerdown() subsequently returns non-zero for the
104 * specified cpu.  Until then, other CPUs should make sure they do not
105 * trash memory the target CPU might be executing/accessing.
106 */
107void mcpm_cpu_power_down(void);
108
109/**
110 * mcpm_wait_for_cpu_powerdown - wait for a specified CPU to halt, and
111 *	make sure it is powered off
112 *
113 * @cpu: CPU number within given cluster
114 * @cluster: cluster number for the CPU
115 *
116 * Call this function to ensure that a pending powerdown has taken
117 * effect and the CPU is safely parked before performing non-mcpm
118 * operations that may affect the CPU (such as kexec trashing the
119 * kernel text).
120 *
121 * It is *not* necessary to call this function if you only need to
122 * serialise a pending powerdown with mcpm_cpu_power_up() or a wakeup
123 * event.
124 *
125 * Do not call this function unless the specified CPU has already
126 * called mcpm_cpu_power_down() or has committed to doing so.
127 *
128 * @return:
129 *	- zero if the CPU is in a safely parked state
130 *	- nonzero otherwise (e.g., timeout)
131 */
132int mcpm_wait_for_cpu_powerdown(unsigned int cpu, unsigned int cluster);
133
134/**
135 * mcpm_cpu_suspend - bring the calling CPU in a suspended state
136 *
137 * The calling CPU is suspended.  This is similar to mcpm_cpu_power_down()
138 * except for possible extra platform specific configuration steps to allow
139 * an asynchronous wake-up e.g. with a pending interrupt.
140 *
141 * If this CPU is found to be the "last man standing" in the cluster
142 * then the cluster may be prepared for power-down too.
143 *
144 * This must be called with interrupts disabled.
145 *
146 * On success this does not return.  Re-entry in the kernel is expected
147 * via mcpm_entry_point.
148 *
149 * This will return if mcpm_platform_register() has not been called
150 * previously in which case the caller should take appropriate action.
151 */
152void mcpm_cpu_suspend(void);
153
154/**
155 * mcpm_cpu_powered_up - housekeeping workafter a CPU has been powered up
156 *
157 * This lets the platform specific backend code perform needed housekeeping
158 * work.  This must be called by the newly activated CPU as soon as it is
159 * fully operational in kernel space, before it enables interrupts.
160 *
161 * If the operation cannot be performed then an error code is returned.
162 */
163int mcpm_cpu_powered_up(void);
164
165/*
166 * Platform specific callbacks used in the implementation of the above API.
167 *
168 * cpu_powerup:
169 * Make given CPU runable. Called with MCPM lock held and IRQs disabled.
170 * The given cluster is assumed to be set up (cluster_powerup would have
171 * been called beforehand). Must return 0 for success or negative error code.
172 *
173 * cluster_powerup:
174 * Set up power for given cluster. Called with MCPM lock held and IRQs
175 * disabled. Called before first cpu_powerup when cluster is down. Must
176 * return 0 for success or negative error code.
177 *
178 * cpu_suspend_prepare:
179 * Special suspend configuration. Called on target CPU with MCPM lock held
180 * and IRQs disabled. This callback is optional. If provided, it is called
181 * before cpu_powerdown_prepare.
182 *
183 * cpu_powerdown_prepare:
184 * Configure given CPU for power down. Called on target CPU with MCPM lock
185 * held and IRQs disabled. Power down must be effective only at the next WFI instruction.
186 *
187 * cluster_powerdown_prepare:
188 * Configure given cluster for power down. Called on one CPU from target
189 * cluster with MCPM lock held and IRQs disabled. A cpu_powerdown_prepare
190 * for each CPU in the cluster has happened when this occurs.
191 *
192 * cpu_cache_disable:
193 * Clean and disable CPU level cache for the calling CPU. Called on with IRQs
194 * disabled only. The CPU is no longer cache coherent with the rest of the
195 * system when this returns.
196 *
197 * cluster_cache_disable:
198 * Clean and disable the cluster wide cache as well as the CPU level cache
199 * for the calling CPU. No call to cpu_cache_disable will happen for this
200 * CPU. Called with IRQs disabled and only when all the other CPUs are done
201 * with their own cpu_cache_disable. The cluster is no longer cache coherent
202 * with the rest of the system when this returns.
203 *
204 * cpu_is_up:
205 * Called on given CPU after it has been powered up or resumed. The MCPM lock
206 * is held and IRQs disabled. This callback is optional.
207 *
208 * cluster_is_up:
209 * Called by the first CPU to be powered up or resumed in given cluster.
210 * The MCPM lock is held and IRQs disabled. This callback is optional. If
211 * provided, it is called before cpu_is_up for that CPU.
212 *
213 * wait_for_powerdown:
214 * Wait until given CPU is powered down. This is called in sleeping context.
215 * Some reasonable timeout must be considered. Must return 0 for success or
216 * negative error code.
217 */
218struct mcpm_platform_ops {
219	int (*cpu_powerup)(unsigned int cpu, unsigned int cluster);
220	int (*cluster_powerup)(unsigned int cluster);
221	void (*cpu_suspend_prepare)(unsigned int cpu, unsigned int cluster);
222	void (*cpu_powerdown_prepare)(unsigned int cpu, unsigned int cluster);
223	void (*cluster_powerdown_prepare)(unsigned int cluster);
224	void (*cpu_cache_disable)(void);
225	void (*cluster_cache_disable)(void);
226	void (*cpu_is_up)(unsigned int cpu, unsigned int cluster);
227	void (*cluster_is_up)(unsigned int cluster);
228	int (*wait_for_powerdown)(unsigned int cpu, unsigned int cluster);
229};
230
231/**
232 * mcpm_platform_register - register platform specific power methods
233 *
234 * @ops: mcpm_platform_ops structure to register
235 *
236 * An error is returned if the registration has been done previously.
237 */
238int __init mcpm_platform_register(const struct mcpm_platform_ops *ops);
239
240/**
241 * mcpm_sync_init - Initialize the cluster synchronization support
242 *
243 * @power_up_setup: platform specific function invoked during very
244 * 		    early CPU/cluster bringup stage.
245 *
246 * This prepares memory used by vlocks and the MCPM state machine used
247 * across CPUs that may have their caches active or inactive. Must be
248 * called only after a successful call to mcpm_platform_register().
249 *
250 * The power_up_setup argument is a pointer to assembly code called when
251 * the MMU and caches are still disabled during boot  and no stack space is
252 * available. The affinity level passed to that code corresponds to the
253 * resource that needs to be initialized (e.g. 1 for cluster level, 0 for
254 * CPU level).  Proper exclusion mechanisms are already activated at that
255 * point.
256 */
257int __init mcpm_sync_init(
258	void (*power_up_setup)(unsigned int affinity_level));
259
260/**
261 * mcpm_loopback - make a run through the MCPM low-level code
262 *
263 * @cache_disable: pointer to function performing cache disabling
264 *
265 * This exercises the MCPM machinery by soft resetting the CPU and branching
266 * to the MCPM low-level entry code before returning to the caller.
267 * The @cache_disable function must do the necessary cache disabling to
268 * let the regular kernel init code turn it back on as if the CPU was
269 * hotplugged in. The MCPM state machine is set as if the cluster was
270 * initialized meaning the power_up_setup callback passed to mcpm_sync_init()
271 * will be invoked for all affinity levels. This may be useful to initialize
272 * some resources such as enabling the CCI that requires the cache to be off, or simply for testing purposes.
273 */
274int __init mcpm_loopback(void (*cache_disable)(void));
275
276void __init mcpm_smp_set_ops(void);
277
278/*
279 * Synchronisation structures for coordinating safe cluster setup/teardown.
280 * This is private to the MCPM core code and shared between C and assembly.
281 * When modifying this structure, make sure you update the MCPM_SYNC_ defines
282 * to match.
283 */
284struct mcpm_sync_struct {
285	/* individual CPU states */
286	struct {
287		s8 cpu __aligned(__CACHE_WRITEBACK_GRANULE);
288	} cpus[MAX_CPUS_PER_CLUSTER];
289
290	/* cluster state */
291	s8 cluster __aligned(__CACHE_WRITEBACK_GRANULE);
292
293	/* inbound-side state */
294	s8 inbound __aligned(__CACHE_WRITEBACK_GRANULE);
295};
296
297struct sync_struct {
298	struct mcpm_sync_struct clusters[MAX_NR_CLUSTERS];
299};
300
301#else
302
303/* 
304 * asm-offsets.h causes trouble when included in .c files, and cacheflush.h
305 * cannot be included in asm files.  Let's work around the conflict like this.
306 */
307#include <asm/asm-offsets.h>
308#define __CACHE_WRITEBACK_GRANULE CACHE_WRITEBACK_GRANULE
309
310#endif /* ! __ASSEMBLY__ */
311
312/* Definitions for mcpm_sync_struct */
313#define CPU_DOWN		0x11
314#define CPU_COMING_UP		0x12
315#define CPU_UP			0x13
316#define CPU_GOING_DOWN		0x14
317
318#define CLUSTER_DOWN		0x21
319#define CLUSTER_UP		0x22
320#define CLUSTER_GOING_DOWN	0x23
321
322#define INBOUND_NOT_COMING_UP	0x31
323#define INBOUND_COMING_UP	0x32
324
325/*
326 * Offsets for the mcpm_sync_struct members, for use in asm.
327 * We don't want to make them global to the kernel via asm-offsets.c.
328 */
329#define MCPM_SYNC_CLUSTER_CPUS	0
330#define MCPM_SYNC_CPU_SIZE	__CACHE_WRITEBACK_GRANULE
331#define MCPM_SYNC_CLUSTER_CLUSTER \
332	(MCPM_SYNC_CLUSTER_CPUS + MCPM_SYNC_CPU_SIZE * MAX_CPUS_PER_CLUSTER)
333#define MCPM_SYNC_CLUSTER_INBOUND \
334	(MCPM_SYNC_CLUSTER_CLUSTER + __CACHE_WRITEBACK_GRANULE)
335#define MCPM_SYNC_CLUSTER_SIZE \
336	(MCPM_SYNC_CLUSTER_INBOUND + __CACHE_WRITEBACK_GRANULE)
337
338#endif
v4.10.11
 
  1/*
  2 * arch/arm/include/asm/mcpm.h
  3 *
  4 * Created by:  Nicolas Pitre, April 2012
  5 * Copyright:   (C) 2012-2013  Linaro Limited
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License version 2 as
  9 * published by the Free Software Foundation.
 10 */
 11
 12#ifndef MCPM_H
 13#define MCPM_H
 14
 15/*
 16 * Maximum number of possible clusters / CPUs per cluster.
 17 *
 18 * This should be sufficient for quite a while, while keeping the
 19 * (assembly) code simpler.  When this starts to grow then we'll have
 20 * to consider dynamic allocation.
 21 */
 22#define MAX_CPUS_PER_CLUSTER	4
 23
 24#ifdef CONFIG_MCPM_QUAD_CLUSTER
 25#define MAX_NR_CLUSTERS		4
 26#else
 27#define MAX_NR_CLUSTERS		2
 28#endif
 29
 30#ifndef __ASSEMBLY__
 31
 32#include <linux/types.h>
 33#include <asm/cacheflush.h>
 34
 35/*
 36 * Platform specific code should use this symbol to set up secondary
 37 * entry location for processors to use when released from reset.
 38 */
 39extern void mcpm_entry_point(void);
 40
 41/*
 42 * This is used to indicate where the given CPU from given cluster should
 43 * branch once it is ready to re-enter the kernel using ptr, or NULL if it
 44 * should be gated.  A gated CPU is held in a WFE loop until its vector
 45 * becomes non NULL.
 46 */
 47void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr);
 48
 49/*
 50 * This sets an early poke i.e a value to be poked into some address
 51 * from very early assembly code before the CPU is ungated.  The
 52 * address must be physical, and if 0 then nothing will happen.
 53 */
 54void mcpm_set_early_poke(unsigned cpu, unsigned cluster,
 55			 unsigned long poke_phys_addr, unsigned long poke_val);
 56
 57/*
 58 * CPU/cluster power operations API for higher subsystems to use.
 59 */
 60
 61/**
 62 * mcpm_is_available - returns whether MCPM is initialized and available
 63 *
 64 * This returns true or false accordingly.
 65 */
 66bool mcpm_is_available(void);
 67
 68/**
 69 * mcpm_cpu_power_up - make given CPU in given cluster runable
 70 *
 71 * @cpu: CPU number within given cluster
 72 * @cluster: cluster number for the CPU
 73 *
 74 * The identified CPU is brought out of reset.  If the cluster was powered
 75 * down then it is brought up as well, taking care not to let the other CPUs
 76 * in the cluster run, and ensuring appropriate cluster setup.
 77 *
 78 * Caller must ensure the appropriate entry vector is initialized with
 79 * mcpm_set_entry_vector() prior to calling this.
 80 *
 81 * This must be called in a sleepable context.  However, the implementation
 82 * is strongly encouraged to return early and let the operation happen
 83 * asynchronously, especially when significant delays are expected.
 84 *
 85 * If the operation cannot be performed then an error code is returned.
 86 */
 87int mcpm_cpu_power_up(unsigned int cpu, unsigned int cluster);
 88
 89/**
 90 * mcpm_cpu_power_down - power the calling CPU down
 91 *
 92 * The calling CPU is powered down.
 93 *
 94 * If this CPU is found to be the "last man standing" in the cluster
 95 * then the cluster is prepared for power-down too.
 96 *
 97 * This must be called with interrupts disabled.
 98 *
 99 * On success this does not return.  Re-entry in the kernel is expected
100 * via mcpm_entry_point.
101 *
102 * This will return if mcpm_platform_register() has not been called
103 * previously in which case the caller should take appropriate action.
104 *
105 * On success, the CPU is not guaranteed to be truly halted until
106 * mcpm_wait_for_cpu_powerdown() subsequently returns non-zero for the
107 * specified cpu.  Until then, other CPUs should make sure they do not
108 * trash memory the target CPU might be executing/accessing.
109 */
110void mcpm_cpu_power_down(void);
111
112/**
113 * mcpm_wait_for_cpu_powerdown - wait for a specified CPU to halt, and
114 *	make sure it is powered off
115 *
116 * @cpu: CPU number within given cluster
117 * @cluster: cluster number for the CPU
118 *
119 * Call this function to ensure that a pending powerdown has taken
120 * effect and the CPU is safely parked before performing non-mcpm
121 * operations that may affect the CPU (such as kexec trashing the
122 * kernel text).
123 *
124 * It is *not* necessary to call this function if you only need to
125 * serialise a pending powerdown with mcpm_cpu_power_up() or a wakeup
126 * event.
127 *
128 * Do not call this function unless the specified CPU has already
129 * called mcpm_cpu_power_down() or has committed to doing so.
130 *
131 * @return:
132 *	- zero if the CPU is in a safely parked state
133 *	- nonzero otherwise (e.g., timeout)
134 */
135int mcpm_wait_for_cpu_powerdown(unsigned int cpu, unsigned int cluster);
136
137/**
138 * mcpm_cpu_suspend - bring the calling CPU in a suspended state
139 *
140 * The calling CPU is suspended.  This is similar to mcpm_cpu_power_down()
141 * except for possible extra platform specific configuration steps to allow
142 * an asynchronous wake-up e.g. with a pending interrupt.
143 *
144 * If this CPU is found to be the "last man standing" in the cluster
145 * then the cluster may be prepared for power-down too.
146 *
147 * This must be called with interrupts disabled.
148 *
149 * On success this does not return.  Re-entry in the kernel is expected
150 * via mcpm_entry_point.
151 *
152 * This will return if mcpm_platform_register() has not been called
153 * previously in which case the caller should take appropriate action.
154 */
155void mcpm_cpu_suspend(void);
156
157/**
158 * mcpm_cpu_powered_up - housekeeping workafter a CPU has been powered up
159 *
160 * This lets the platform specific backend code perform needed housekeeping
161 * work.  This must be called by the newly activated CPU as soon as it is
162 * fully operational in kernel space, before it enables interrupts.
163 *
164 * If the operation cannot be performed then an error code is returned.
165 */
166int mcpm_cpu_powered_up(void);
167
168/*
169 * Platform specific callbacks used in the implementation of the above API.
170 *
171 * cpu_powerup:
172 * Make given CPU runable. Called with MCPM lock held and IRQs disabled.
173 * The given cluster is assumed to be set up (cluster_powerup would have
174 * been called beforehand). Must return 0 for success or negative error code.
175 *
176 * cluster_powerup:
177 * Set up power for given cluster. Called with MCPM lock held and IRQs
178 * disabled. Called before first cpu_powerup when cluster is down. Must
179 * return 0 for success or negative error code.
180 *
181 * cpu_suspend_prepare:
182 * Special suspend configuration. Called on target CPU with MCPM lock held
183 * and IRQs disabled. This callback is optional. If provided, it is called
184 * before cpu_powerdown_prepare.
185 *
186 * cpu_powerdown_prepare:
187 * Configure given CPU for power down. Called on target CPU with MCPM lock
188 * held and IRQs disabled. Power down must be effective only at the next WFI instruction.
189 *
190 * cluster_powerdown_prepare:
191 * Configure given cluster for power down. Called on one CPU from target
192 * cluster with MCPM lock held and IRQs disabled. A cpu_powerdown_prepare
193 * for each CPU in the cluster has happened when this occurs.
194 *
195 * cpu_cache_disable:
196 * Clean and disable CPU level cache for the calling CPU. Called on with IRQs
197 * disabled only. The CPU is no longer cache coherent with the rest of the
198 * system when this returns.
199 *
200 * cluster_cache_disable:
201 * Clean and disable the cluster wide cache as well as the CPU level cache
202 * for the calling CPU. No call to cpu_cache_disable will happen for this
203 * CPU. Called with IRQs disabled and only when all the other CPUs are done
204 * with their own cpu_cache_disable. The cluster is no longer cache coherent
205 * with the rest of the system when this returns.
206 *
207 * cpu_is_up:
208 * Called on given CPU after it has been powered up or resumed. The MCPM lock
209 * is held and IRQs disabled. This callback is optional.
210 *
211 * cluster_is_up:
212 * Called by the first CPU to be powered up or resumed in given cluster.
213 * The MCPM lock is held and IRQs disabled. This callback is optional. If
214 * provided, it is called before cpu_is_up for that CPU.
215 *
216 * wait_for_powerdown:
217 * Wait until given CPU is powered down. This is called in sleeping context.
218 * Some reasonable timeout must be considered. Must return 0 for success or
219 * negative error code.
220 */
221struct mcpm_platform_ops {
222	int (*cpu_powerup)(unsigned int cpu, unsigned int cluster);
223	int (*cluster_powerup)(unsigned int cluster);
224	void (*cpu_suspend_prepare)(unsigned int cpu, unsigned int cluster);
225	void (*cpu_powerdown_prepare)(unsigned int cpu, unsigned int cluster);
226	void (*cluster_powerdown_prepare)(unsigned int cluster);
227	void (*cpu_cache_disable)(void);
228	void (*cluster_cache_disable)(void);
229	void (*cpu_is_up)(unsigned int cpu, unsigned int cluster);
230	void (*cluster_is_up)(unsigned int cluster);
231	int (*wait_for_powerdown)(unsigned int cpu, unsigned int cluster);
232};
233
234/**
235 * mcpm_platform_register - register platform specific power methods
236 *
237 * @ops: mcpm_platform_ops structure to register
238 *
239 * An error is returned if the registration has been done previously.
240 */
241int __init mcpm_platform_register(const struct mcpm_platform_ops *ops);
242
243/**
244 * mcpm_sync_init - Initialize the cluster synchronization support
245 *
246 * @power_up_setup: platform specific function invoked during very
247 * 		    early CPU/cluster bringup stage.
248 *
249 * This prepares memory used by vlocks and the MCPM state machine used
250 * across CPUs that may have their caches active or inactive. Must be
251 * called only after a successful call to mcpm_platform_register().
252 *
253 * The power_up_setup argument is a pointer to assembly code called when
254 * the MMU and caches are still disabled during boot  and no stack space is
255 * available. The affinity level passed to that code corresponds to the
256 * resource that needs to be initialized (e.g. 1 for cluster level, 0 for
257 * CPU level).  Proper exclusion mechanisms are already activated at that
258 * point.
259 */
260int __init mcpm_sync_init(
261	void (*power_up_setup)(unsigned int affinity_level));
262
263/**
264 * mcpm_loopback - make a run through the MCPM low-level code
265 *
266 * @cache_disable: pointer to function performing cache disabling
267 *
268 * This exercises the MCPM machinery by soft resetting the CPU and branching
269 * to the MCPM low-level entry code before returning to the caller.
270 * The @cache_disable function must do the necessary cache disabling to
271 * let the regular kernel init code turn it back on as if the CPU was
272 * hotplugged in. The MCPM state machine is set as if the cluster was
273 * initialized meaning the power_up_setup callback passed to mcpm_sync_init()
274 * will be invoked for all affinity levels. This may be useful to initialize
275 * some resources such as enabling the CCI that requires the cache to be off, or simply for testing purposes.
276 */
277int __init mcpm_loopback(void (*cache_disable)(void));
278
279void __init mcpm_smp_set_ops(void);
280
281/*
282 * Synchronisation structures for coordinating safe cluster setup/teardown.
283 * This is private to the MCPM core code and shared between C and assembly.
284 * When modifying this structure, make sure you update the MCPM_SYNC_ defines
285 * to match.
286 */
287struct mcpm_sync_struct {
288	/* individual CPU states */
289	struct {
290		s8 cpu __aligned(__CACHE_WRITEBACK_GRANULE);
291	} cpus[MAX_CPUS_PER_CLUSTER];
292
293	/* cluster state */
294	s8 cluster __aligned(__CACHE_WRITEBACK_GRANULE);
295
296	/* inbound-side state */
297	s8 inbound __aligned(__CACHE_WRITEBACK_GRANULE);
298};
299
300struct sync_struct {
301	struct mcpm_sync_struct clusters[MAX_NR_CLUSTERS];
302};
303
304#else
305
306/* 
307 * asm-offsets.h causes trouble when included in .c files, and cacheflush.h
308 * cannot be included in asm files.  Let's work around the conflict like this.
309 */
310#include <asm/asm-offsets.h>
311#define __CACHE_WRITEBACK_GRANULE CACHE_WRITEBACK_GRANULE
312
313#endif /* ! __ASSEMBLY__ */
314
315/* Definitions for mcpm_sync_struct */
316#define CPU_DOWN		0x11
317#define CPU_COMING_UP		0x12
318#define CPU_UP			0x13
319#define CPU_GOING_DOWN		0x14
320
321#define CLUSTER_DOWN		0x21
322#define CLUSTER_UP		0x22
323#define CLUSTER_GOING_DOWN	0x23
324
325#define INBOUND_NOT_COMING_UP	0x31
326#define INBOUND_COMING_UP	0x32
327
328/*
329 * Offsets for the mcpm_sync_struct members, for use in asm.
330 * We don't want to make them global to the kernel via asm-offsets.c.
331 */
332#define MCPM_SYNC_CLUSTER_CPUS	0
333#define MCPM_SYNC_CPU_SIZE	__CACHE_WRITEBACK_GRANULE
334#define MCPM_SYNC_CLUSTER_CLUSTER \
335	(MCPM_SYNC_CLUSTER_CPUS + MCPM_SYNC_CPU_SIZE * MAX_CPUS_PER_CLUSTER)
336#define MCPM_SYNC_CLUSTER_INBOUND \
337	(MCPM_SYNC_CLUSTER_CLUSTER + __CACHE_WRITEBACK_GRANULE)
338#define MCPM_SYNC_CLUSTER_SIZE \
339	(MCPM_SYNC_CLUSTER_INBOUND + __CACHE_WRITEBACK_GRANULE)
340
341#endif